Clojurians Log v2

I am using malli.core/=> for function schema validation, I am able to handle standard fn-arguments with their respective validator-fn but how can I handle variadic arguments. A sample code

(malli.core/=> fn-with-variadic-args
               [:=> [:cat {:malli/fn-name with-var-args} int? string? int?] any?])

(defn fn-with-variadic-args
  [int-val string-val int-val' & [map-val]]
  (prinlnt (format "%s:%s => {%s}" string-val (+ int-val int-val') (:string-value map-val))))

I am getting `Invalid function arity` exception staging expected 3 got 4